Good news! It Has Changed The Earth Will Not Be Swallowed By The Sun

Some good news and other bad news. The good news is that, contrary to previous fears, The world they may never be swallowed the sun. The bad news, of course, is that none of us will be around to find out.

Scientists have long estimated that in about 5 billion years, the sun will run out of fuel, first becoming a red giant and eventually a white giant that will continue to cool for tens—or hundreds—of billions of years. In the midst of this strange sequence of cosmic events, the future of Earth is uncertain.

Will it be drawn into the expanding red sun and disappear forever? Or, even though it has long been uninhabited, will it continue to orbit the small, white remnant Sun until the sky reaches its final temperature?

Until now, the prevailing opinion among astronomers favored early events. But a new study published in Astronomy & Astrophysics reverses that expectation, and provides new evidence that Earth may survive the solar transition into a red giant.

Soul of the Sun

To understand what will happen to the planets around the sun, you have to look inside the sun itself. Right now, the sun is in its main phase, a stable atmosphere lasting for about 4.5 billion years, which is driven mainly by the fusion of hydrogen into helium.

This phase will continue for billions of years, but gradually the sun will become hotter and brighter. Eventually, it will become bright enough to melt all the water on Earth, rendering our planet uninhabitable in the next two billion years.

About 5 billion years from now, the long solar system will end. At that time, the hydrogen inside it will be gone. The helium core condenses under its own gravity, heating up and causing hydrogen fusion in the surrounding shell. The result is that the outer layers of the sun will grow larger as the surface cools, giving the red color of this stage in the evolution of stars. And this is where the mystery surrounding the world begins.

Dragging the Hardest Battle

The massive expansion of the sun will dramatically change the orbit of the earth due to the interaction of two opposing forces. On the other hand, the sun will lose a lot of energy due to strong interstellar winds. As gravity weakens, the Earth’s orbit slowly moves outward. On the other hand, the planet’s proximity to the sun produces more gas that produces energy, while tidal forces—the difference in the gravitational force that affects the near and far sides of an object, which can gradually change the movement of the planets—will act as brakes on the movement of the Earth.

To this day, scientists consider it highly probable that this will rule. During this time, the Earth would gradually lose orbital momentum, rotate inward, and eventually be engulfed by the expanding Sun, where it would evaporate completely.

A New Hope

The new study, based on tidal accretion and the loss of stars from the sun during the evolution of a red giant, proves another point. According to the researchers, the loss of waves – a process that produces orbital energy and gradually causes elliptical orbits, such as Earth, to become circular – may not be more effective than previous models.

At the same time, the sight of the red giant L2 Sonwhich is at a distance of about 209 years from Earth, shows that the sun can lose enough energy for this to happen than the energy of the waves. If so, the planet’s orbit will gradually move outward, increasing its chances of surviving the red giant phase.

An Uncertain Future

Although this research is very promising, the future of the world is not certain. The characteristics of the stellar wind and temperature fluctuations that occur at the end of a star’s evolution include many variables that are difficult to predict accurately. If the sun lost less energy than the new model assumes, the tidal force would remain, pulling the Earth inward and causing it to collapse.

While the future of Earth is still an open question, the outlook for the rest of the planet is becoming increasingly clear. As the Sun expands, Mercury and Venus will be surrounded by its outer layers, forever disappearing due to extreme heat and tidal forces. But the outer planets will follow a different path. On Mars, although there will be a dramatic rise in temperature that causes permanent ice, moving to a more remote location will avoid physical damage.

In the distance, the gas giants Jupiter and Saturn will see the paths of their moons altered, while increased solar radiation may temporarily melt the ice of moons such as Europa and Enceladus, creating liquid oceans on their surfaces. Which means that these countries – for a while – could be the successors of the Blue Planet after Earth turned into a barren wasteland.

This article appeared first WIRED Italy and translated from Italian.